[HusamEddin]

Hi there,
Is it possible to prepare 2-pentanol from n-butanol ?
even if it is indirect , is it possible ?

waiting and thanks

[sjb]

Hi there,
Is it possible to prepare 2-pentanol from n-butanol ?
even if it is indirect , is it possible ?

waiting and thanks

Can you suggest ways to make pentan-2-ol from anything?

[HusamEddin]

treating 2-pentene with h2o .. this is simple,
also I saw some reactions on the internet begining with formaldehyde
they are all clear to me
but this one, begining from n-butanol, it is somehow difficult
has Grigrand reagent anything to do with this problem ?

[sjb]

treating 2-pentene with h2o .. this is simple,
also I saw some reactions on the internet begining with formaldehyde
they are all clear to me
but this one, begining from n-butanol, it is somehow difficult
has Grigrand reagent anything to do with this problem ?

OK, so how can you make pent-2-ene? Grignards are a possible other route to explore.

[HusamEddin]

dehydration of alcohol pentanol will give me 2-pentene, but what does this suppose to do with our problem ?

[sjb]

OK, so it's possible that pent-2-ene is a dead end. Any other ways to make pentan-2-ol? What would you need for your Grignard route?

[HusamEddin]

about grignard , I solved it, it is all clear
but the issue is that we've not started yet with "Aldehydes & Ketones" chapter, all what I got are
Alkanes Alkenes Alkynes, Alcohols Phenols Thiols Ethers & Epoxides
thus when I asked, I just wanted to know if there is any route to solve the problem using reactions from these chapters, but not ketones & aldehydes
Is there a way ?

thanks

[Hunter2]

Butanol => 1-Chlorine-Butane  => 1-Butylcyanide  => Pentane acid => 1- Pentanole

Or Arndt-eistert http://www.organic-chemistry.org/namedreactions/arndt-eistert-synthesis.shtm

Grignard and Carbondioxide

[HusamEddin]

Butanol => 1-Chlorine-Butane  => 1-Butylcyanide  => Pentane acid => 1- Pentanole

Or Arndt-eistert http://www.organic-chemistry.org/namedreactions/arndt-eistert-synthesis.shtm

Grignard and Carbondioxide

eventually, you gave me off a primary pentanol not secondery >>> I want the later

[TheOrganic]

Predict the product of the following reactions:

1. Formaldehyde treated with methyl grignard, followed by hydrolysis.
2. Acetaldehyde treated with methyl grignard, followed by hydrolysis.
3. Acetone treated with methyl grignard, followed by hydrolysis.

If you do not know the above reactions, look up.

Now try to answer the following questions:

(i) What is the common class of products all three of these will produce?
(ii) What is the position of the functional group in each case?
(iii) Which starting material gave the functional group in that position, in each case?
(iv) Can you see a pattern? Can you apply the pattern to your problem?
(v)  What are the oxidation levels of the starting material and the product in your original problem? What is the oxidation level of the starting materials and products in this pattern ?
(vi) If you were to use this pattern, you would need an intermediate. How would you reach that intermediate?

Try. You'll be able to do it yourself. If you get stuck, we are here to help.

[Hunter2]

In Post 7 it was pointed out, that they don't had the chaptor about Aldehyde or ketones.

[TheOrganic]

In Post 7 it was pointed out, that they don't had the chaptor about Aldehyde or ketones.

As far as I can recall, when we were learning " Synthesis of Alcohols " we were actually learning reactions between carbonyls and grignard reagent, and I believe that is the way it should be taught. Even if the course demands some other answer to the problem, I'd advice a student to learn the Grignard synthesis for alcohols.

Regarding the non-gragnard route, there could be numerous approaches to this synthesis.

To keep things simple, since this requires increase in carbon chain length, I'd go for an alkyne of the same length first, and increase the chain length using some alkyl halide.  I can then see a controlled reduction followed by some kind of hydration ( most probably hydroboration followed by oxidation ) would be required to get the desired product.

Try this method, then.